恢复策划 Agent 实时事件订阅（876529e66 误删）

- apps/ai-game-creator-shell/src/App.tsx 重新订阅 `design-agent-update`：本轮正文与工具提示回到 transient reply，`reasoningText` 回到 `planningV2Reasoning`，`view` 回到 applyDesignAgentViewAfterTransient；Rust 侧一直照旧发射这些事件，前端却不再监听
- 补回 designAgentEventSubscriptionReadyRef 的建/解函数与 designAgentEventSubscriptionResolveRef，让 `executeDesignAgentTurn` 等待监听器挂好再发起回合，开局事件不丢
- 新增 designAgentReasoningTurnRef：回合结束（designAgentTurnRef 清空）后仍认本轮 reasoning，最后一条思考不会被视图落盘前的空隙吃掉；切项目时随 resetChatState 清空

apps/ai-game-creator-shell/src/App.tsx

@@ -33,6 +33,7 @@ import type {
   ChatMessage,
   DesignAgentInput,
   DesignClarificationRequest,
+  DesignEvent,
   DesignView,
   InitLocalProjectResult,
   LauncherImportedAttachment,
@@ -102,6 +103,10 @@ import {
   setAgcPluginProjectPath,
   startAvailableAgcPlugin,
 } from './services/pluginHost';
+import {
+  canSubscribeTauriEvents,
+  subscribeTauriEvent,
+} from './services/tauriEventSubscription';
 import type { HomeCreationType } from './view/home';
 import {
   type ProjectAgentResultSummary,
@@ -243,6 +248,20 @@ export function App({
   const designAgentEventSubscriptionReadyRef = useRef<Promise<void> | null>(
     null,
   );
+  const designAgentEventSubscriptionResolveRef = useRef<(() => void) | null>(
+    null,
+  );
+  /**
+   * 本轮策划回合的思考归属。
+   *
+   * 与 `designAgentTurnRef` 分开：那个记录回合本身，回合结束就清空；这个只用来判定
+   * 「这条 reasoning 事件是不是本轮的」，回合结束后仍保留，最后一条思考不会在视图
+   * 落盘前的空隙里被丢掉。切项目时随其它聊天状态一起清空。
+   */
+  const designAgentReasoningTurnRef = useRef<{
+    projectPath: string;
+    clientTurnId: string;
+  } | null>(null);
   // 项目开发工作台的普通项目固定使用 DirectProject，立项策划项目走策划聊天；两条
   // 链路各自独立，不通过兼容分支互相承载。
   const directProjectMode = !planningV2Active;
@@ -419,6 +438,22 @@ export function App({
     return designAgentEventSubscriptionReadyRef.current ?? Promise.resolve();
   }
 
+  function createDesignAgentEventSubscriptionReady() {
+    if (!designAgentEventSubscriptionReadyRef.current) {
+      designAgentEventSubscriptionReadyRef.current = new Promise<void>(
+        (resolve) => {
+          designAgentEventSubscriptionResolveRef.current = resolve;
+        },
+      );
+    }
+    return designAgentEventSubscriptionReadyRef.current;
+  }
+
+  function resolveDesignAgentEventSubscriptionReady() {
+    designAgentEventSubscriptionResolveRef.current?.();
+    designAgentEventSubscriptionResolveRef.current = null;
+  }
+
   useEffect(() => {
     const timer = window.setInterval(() => {
       const target = planningV2TransientReplyTargetRef.current;
@@ -442,6 +477,83 @@ export function App({
     return () => window.clearInterval(timer);
   }, []);
 
+  /**
+   * 策划 Agent 的实时事件流：本轮流式正文、思考过程和回合中途的视图都靠它推给界面。
+   *
+   * 订阅建立是异步的，而回合由一个 invoke 发起；`designAgentEventSubscriptionReady()`
+   * 让回合等监听器挂好再开始，避免开头几个事件丢掉。事件只认当前项目；有在跑的回合时
+   * 还要认本轮 `clientTurnId`，迟到的上一轮事件不会画到这一轮上。
+   */
+  useEffect(() => {
+    const ready = createDesignAgentEventSubscriptionReady();
+    if (!canSubscribeTauriEvents() || !planningV2Active) {
+      resolveDesignAgentEventSubscriptionReady();
+      return () => {
+        if (designAgentEventSubscriptionReadyRef.current === ready) {
+          designAgentEventSubscriptionReadyRef.current = null;
+          createDesignAgentEventSubscriptionReady();
+        }
+      };
+    }
+    let cleanup: (() => void) | null = null;
+    let disposed = false;
+    void subscribeTauriEvent<DesignEvent>('design-agent-update', (event) => {
+      const payload = event.payload;
+      const tracked = designAgentTurnRef.current;
+      if (
+        payload.projectPath !== localProjectPathRef.current ||
+        (tracked && payload.clientTurnId !== tracked.clientTurnId)
+      ) {
+        return;
+      }
+      if (
+        (payload.kind === 'text' || payload.kind === 'tool') &&
+        payload.text
+      ) {
+        setPlanningV2TransientReplyTarget(payload.text);
+      }
+      if (payload.reasoningText != null) {
+        const reasoningTurn = designAgentReasoningTurnRef.current;
+        if (
+          reasoningTurn?.projectPath === payload.projectPath &&
+          reasoningTurn.clientTurnId === payload.clientTurnId
+        ) {
+          setPlanningV2Reasoning(payload.reasoningText);
+        }
+      }
+      if (payload.view) {
+        applyDesignAgentViewAfterTransient(
+          payload.view,
+          payload.projectPath,
+          payload.clientTurnId,
+        );
+      }
+    })
+      .then((unlisten) => {
+        resolveDesignAgentEventSubscriptionReady();
+        if (disposed) {
+          unlisten();
+          return;
+        }
+        cleanup = unlisten;
+      })
+      .catch(() => {
+        resolveDesignAgentEventSubscriptionReady();
+      });
+    return () => {
+      disposed = true;
+      cleanup?.();
+      resolveDesignAgentEventSubscriptionReady();
+      if (designAgentEventSubscriptionReadyRef.current === ready) {
+        designAgentEventSubscriptionReadyRef.current = null;
+        createDesignAgentEventSubscriptionReady();
+      }
+    };
+    // 订阅只跟着「是否走策划 Agent」这条链路；回调里的项目/回合判据都走 refs，
+    // 把它们写进依赖会在每轮回复时重订事件。
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [planningV2Active]);
+
   function applyPlanningV2CommandResult(
     result: PlanningSessionCommandResultV2,
     clientTurnId?: string,
@@ -712,6 +824,10 @@ export function App({
       projectPath: nextProjectPath,
       clientTurnId,
     };
+    designAgentReasoningTurnRef.current = {
+      projectPath: nextProjectPath,
+      clientTurnId,
+    };
     designAgentPendingViewRef.current = null;
     await designAgentEventSubscriptionReady();
     setChatAgentBusy(true);
@@ -1582,6 +1698,7 @@ export function App({
     planningV2ActiveRef.current = planningStartMode;
     designAgentLaneRef.current = planningStartMode;
     designAgentTurnRef.current = null;
+    designAgentReasoningTurnRef.current = null;
     setDesignAgentView(null);
   }
 
@@ -2689,6 +2806,10 @@ export function App({
                   projectPath: nextProjectPath,
                   clientTurnId,
                 };
+                designAgentReasoningTurnRef.current = {
+                  projectPath: nextProjectPath,
+                  clientTurnId,
+                };
                 designAgentPendingViewRef.current = null;
                 setPlanningV2TransientReplyTarget('');
                 setPlanningV2Reasoning('');